Conventionally, image formation apparatus such as digital copying machines for processing digitized image data developed from analog copying machines and, color copying machines capable of making color prints as well as monochromatic prints have been widely used and distributed. The color copying machine generally consists of a scanner for inputting a draft image, an IPU for carrying out various kinds of image processing for the inputted image data, and a printer for printing the processed image data onto a sheet of transcription paper to output the draft image.
Prior to the shipment of these color copying machines from a plant, the scanner and the printer of each color copying machine are calibrated to set the image processing parameters in the IPU and the printer, so that the color copying machine can print a copy of a draft having a good reproducibility of colors. Thus, the color copying machines with its calibrated image processing parameters, are provided to users, and the color copying machines will print using these preset image processing parameters.
Further, along the recent development of communication technologies, the environments of the color copying machines have changed substantially. A large-scale image formation system capable of achieving data transmission/reception between a plurality of color copying machines has been produced by connecting a plurality of color copying machines together via the Internet or the like.
Using this large-scale image formation system, it is possible to transmit an image data read by the scanner of one color copying machine to another color copying machine, and the IPU and the printer of the color copying machine that has received this image data will carry out image processing and print the received image.
When it is desired to make a large volume of copies from only one existing draft in a short period of time, for example, it is possible for the scanner of one color copying machine to read the draft and transmit the read image data to a plurality of other color copying machines, which will simultaneously perform the image processing and print multiple copies of the received image data.
Further, it is desired to collect and integrally manage at one location a number of drafts that exists at a plurality of locations. For example, it is possible for the scanners of a plurality of color copying machines to read these drafts, and these color copying machines transmit the read image data to one color copying machine. This color copying machine carries out the image processing and prints the received image data.
However, when the conventional copy machine technology is used, the color reproducibility of printed materials is degraded when a plurality of color copying machines are connected together to transmitter receive data. If draft images are printed by a color copying machine which has not read the draft, the images are different from those that are printed by a color copying machine which has initially read the draft.
In other words, image processing parameters used for the image processing in a color copying machine are obtained by calibrating a scanner and a printer of a particular color copying machine at same time as a single set. Not all color copying machines have the same image processing parameters. In the conventional technique, the color copying machine that performs the image processing and prints is different from the color copying machine that reads the draft. Therefore, the combination of the scanner that has read the draft and the printer that carries out the printing is different from a combination of the scanner and the printer that have been calibrated together. As a result, when the image processing parameters of a color copying machine that has read the draft are different from the image processing parameters of a color copying machine that has received the image data, there has been a problem of degradation in the color reproducibility of the printed materials, as compared with the method of printing the image data by a single color copying machine that both reads and prints the draft.
This problem becomes more extreme in the case where, in order to make a large volume of copies from only one existing draft in a short period of time, a scanner of one color copying machine reads the draft, and then the color copying machine transmits the read image data to a plurality of other color copying machines. The color copying machines then carry out image processing and print the received image data. In other words,—the color reproducibility of the printed materials, when using the conventional copying technique, in which scanning and printing are done by separate machines, is worse than the image scanned and printed by a single color copying machine. Therefore, there has been a problem that a large volume of printed materials not having uniform color reproducibility is produced.
Similarly, the problem of the conventional copying technique becomes more extreme in the case where, in order to print all the drafts integrally at one location, the drafts that exist at a plurality of locations, are scanned by the scanners of a plurality of color copying machines, and the scanned images are then transmitted to another color copying machine where image processing is carried out and all the final drafts are printed.